Balanced valve.



G. A. CUMMINGS.

. BALANCED VALVE.

APPLICATION FILED DEC. 28, 1909.

1,000,588, Patented Aug. 15, 1911 Q Inventor? I Clarence fl. kzmmz'nys.witnesses. Q f? 0 r a Attorneys.

V UNITED. srn'rns PATENT m CLARENCE A. CUMMINGS, 0F FRESNO,GALIIEOIEtll'IA BALANCED vALvE.

Specification of Letters Patent. Pat nt d Qug Application filed December28, 1909; Serial No. 535,243.. t

To all whom it may concern:

Be it known that 1,-CLARENCE A. CUM- times, a 'citiz'eno'f the UnitedStates, residsuch a way that, although subjected on one side to a highpressure and on the other side to a comparatively'low'pressure,the'valve will be balanced sothat the force necessary .to adjustthe'degree of opening of thefvalve will be relatively small, that is,such a force as could be exerted by a gas or liquidfunder a lowpressure. X p

The invention consists in the construc tion and combination of parts tobe more fully described hereinafter and I particularly set forth in theclaims. j

In the annexed drawing which fully illustrates my invention, Figure 1 isa I longitudinal vertical section through a valve con-- structedaccording to my invention and through the pressure regulator whichisused in connection therewith, certain parts being broken awayandpartly shown in elevation. Fig.2 is aplan of the slide or piston whichforms the valve gate,-the packing rings being removed. I y

} Referring more particularly to thedrawis in the form, of a cut oil orslide valve having an elongated body 4: provided with a longitudinalbore 5, said bore being closed by removable heads 6 provided withsuitable stufiing boxes 7. Through one of the stufling boxes 7 a valvestem 8 extends, and at the opposite end a tail stem or tail rod 9 isprovided which is of'the same diameter as the stem '8'. In the bore 5 aslide or piston 10 is mounted which'is ofv cylindrical form fittingclosely in the bore as indicated. Near its .ends this piston is'providedwith packing rings 11 bfany suitable forin as shown, On its upper sidethe valve body is'provided withan inlethub'or boss 12fat an inlet pipej13 "indicated in dotted lines is attached, and this" inlet pipe is slppag -(15a carry a-gas or liquid-under a relatively high pressure.

ing,'3 represents the balanced valve which piston and the heads 6.

Thefunder side of the body 4 is formed into an outlet hub l l; havingaver.

tical bore or discharge opening 15 andthis hub 14 is mounted upon asuitable base 16 having a duct 17 communicating with the discharge oroutlet 15, and also communicating with the partof the apparatus underlow pressure;

vOn its upper side the piston or slide 10 provided with an inlet port 18which ex- 7 tends downwardly into the interior of the," sl de andconnects with a short longit-udil nally extending passage 19 in theinterior f of the slide,

connects with the port 18 as shown, and'the One end of this passage-"19other, end connects with an outlet port 20- formed on the under sideof-the gate. In, th1s way the ports 18 and 20 areofiset from.

each other. These ports and the. passage 1'9.v connecting them are ofthe same width meas-v urcd transversely of theslide, as indicated inFig. 2.

As shown in 1, the length of the port:-

18 is substantially equal to'the width or diameter of the outlet 15, andthe port 20, is of less length measured longitudinally ofthe valve. Itwill be seen that the passage 19 and the ports 18 and-2O forman offsetduct passing through the piston, that is, the ports 18 and 20 are notopposite to each other. Furthermore, onvaccount of the dif surface 22 onthe under side of thepassage.

This excess of areais very'slight, however,

and its purpose will appear morefully here; inafter. i A

'ference in length of the ports 18 and 20, T the passage 19 presents asurface 21 on, its, upper side which is of less area than the in whichitslides so that'the chambers 23 and 2 1 are formed between the ends ofjth e- These chambers 23 and 24: are in communication with the.

outlet 15 through pipe connections 25 ar ranged as shown. The valve stem8 1s ad I ustably connected at its end with the end of a rack 26 whichlis v, "mounted to slide longitudinally on suitable ,guide. posts 27attached'to a base plate or bracket [28. This rack26 has teeth on itsvupper side which mesh with a gear wheel 29 which is mounted o nvi'ahorizontal'jpivotpin 30 secured in the; upper end of a post 31, whichpost is also mounted on" th base plate 28. The gear wheel 29 is providedwith radial slots 32 in one of which a regulator stem 33 is adjustablyattached by means of a suitable pin 34. This regulator stem 33 extendsinto the interior of a pressure regulator 35. This pressure regulator 35has a body 36, enlarged at its outer end to form a chamber 37, saidchamber being provided with a diaphragm 38 held in position by asuitable cover 39. It is also provided with a tubular neck 40 of reduceddiameter which extends toward the gear wheel, and-through this neck 40the stem 33 extends inwardly as suggested, the inner end of the stembeingattached to the diaphragm 38 near its center. Near the diaphragm 38a collar 41 is fixed on the stem .33 and a coiled spring 42 is arrangedso that its inner end thrusts against this collar so .as to resist themovement of the diaphragm in the direction of the gear wheel. The outerend of this spring thrusts against a cap 43 which screws on the end ofthe tubular neck 40 and havlng an enlarged opening 44 through which thestem 33 passes as shown. The regulator body 36 is suitably mounted on anupward extension or arm 45 fOlmlIlg part of the base plate 28.

As shown. the inner face of the cover 39 is formed with aslight-depression or dish 4'6 so that a part of the chamber 37 is cutoff to form a pressure chamber 47. The cover is provided witha centralopening 48 which communicates with this pressure chamber 47 and at thisopening a pipe connection 49 is attached, the other end of whichconnects with an opening 50 which is in communication withthe duct 17,that is,'it is in communication withthe low pressure side of the systemin which the valve is employed.

The mode of operation of the valve and pressure regulator will now bedescribed.

In this connection it should be understood that the pressure regulatoris controlled automatically by the pressure existing in the low pressuresystem, that is, I control the degree of opening of the valve piston 10by variations of this low pressure. It will be seen that u'pona rise ofpressure in the low pressure system the diaphragm 38 will be movedtoward the left. This will rotate the gear wheel 29 in a left handdirection moving the rack 26 toward the right.

This will move the piston 10' toward the right and advance the cut-01fedge 51 of the piston toward the right at the outlet 15.

In this way the degree of opening at this point will be reduced. Thisreduction of the effective port opening at the port 20 will reduce thepressure existing on the low pressure side of the valve. In this way thepres sure regulator and the'valve cooperate. so as to maintain thepressure on the low pressure side of the system at a substantiallyconstant point.

-Attention is called to the enlarged port 18 and this feature is ofgreat importance in securing the balanced effect in the valve 3,

for the reason that it substantially prevents any application of thehigh pressure gas or liquid to the upper side face of the piston 10. Onaccount of the fact that the surface 22 is slightly in excess of thesurface 21 in area,

it follows that the gas or liquid in the passage 19 exerts a slightdownward pressure on the piston 10. In other words, with respect to itsinterior, the valve is slightly unbalanced sothatthere is a slightexcess of downwardly exerted force on itsupper side. This excess ofpressure or downward force is balanced however, by. the pressure exertedon the,low pressure side, which pressure is applied to the under side ofthe valve at the point where the cut-0H edge 51 overhangs the outlet 15.In this way I produce a substantially balancedpiston or gate which willrequire a very small force to'slide it. It will be understood for thesereasons that this apparatus will be very sensitive to slight changes inpressure on the low pressure side of the system.

The ends of the piston 10 are of course balanced by the equality inpressure existing in the chambers 23 and 2. and in this connection itshould be noted that the areas exposed to pressure through the pipeconnections 25 are equal.

Having described my invention, what I claim as new and desire to secureby Letters Patent, is I 1. A balanced valve comprising a body, a gatesliding within said body and provided with a duct passing transverselythere through, said duct having a passage ext-ending longitudinally ofsaid gate and having an enlarged opening on the side of said gatedisposed toward the high pressure admis: sion point, said gate having asingle opening of reduced size with respect to said enlarged openingdisposed on the side of said gate to-' ward the low pressure side ofsaid gate, said passage having an area on its upper side exposed to thepressure within said duct tending to press said gate toward the highpressure side of said valve, and also having an area exposed to thehighpressure and tending to force said gate toward the low pressure side,said gate being arranged to cutoff on the low pressure side, saidareasbeing arranged so that the pressure on said gate from the lowpressure side substantially balances the pressure on the high pressureside.

2. A balanced valve having a valve body with a high pressure connectionon the upper side thereof and a low pressure connection on the" underside thereof, said high 1 of enlarged diameter, a gate sliding in saidbod-y having a duct passing transversely therethrough, sa1d ductcomprlslng a passage extending longitudinally, having a port on theupper sidecommunicating'with said high pressure connection and having aport on the lower side communicating with said low pressure connection.

3. A balanced valve having a body with a high pressure connection ofreduced dimension on the upper side thereof, a low pressure connectionof enlarged dimension on the under side thereof, a gate mounted to slidein said body having a longitudinal passage presenting substantiallyhorizontal surfaces of unequal areas, and having a port on its upperside constantly maintaining communication between said passage and saidhigh pressureconnection, said duct having a cut oif port on its underside communieating with said, low pressure connection. I

4. A balanced valve. comprising a body, a gate sliding within saidbodyprovided with a duct passing transversely therethrough and having apassage extending longitudinally therein, saidv body having a highpressureconnection on one side of said gate and having a lowpressureconnection on the opposite side of said gate, said passagehaving an area on its upper side exposed to the pressure withinsaid ducttending to press said gate toward the high pressure side of said valveand-also having an area exposed to the high pressure and tending toforce said gate toward the low pressure side, said piston being arrangedto cut oil" on the low pressure side, said areas being arranged. so thatthe pressure on said gate from the low pressure side substantially bal'ances said gate; said valve body having chambers in the ends thereofbeyond said gate and means for maintaining equality of pressure in saidchambers. 5: A balanced valve comprising a body,

a gate sliding within said body provided with a duct passingtransversely therethrough and having a passage extending longitudinally.therein, said body having a high pressure connection on one side ofsaid gate and having a low yressure connection on the opposlte side ofsaid gate, sald passage havmg an area on its upper slde exposed to thepressure within said duct tend ing to press said gate toward the highpres sure side of said valve-and also having an area exposed to the highpressure and tending to force said gate toward the low pressure side,said piston being arranged to cut' off on the low pressure side, saidareas being arranged so that the pressure on said gate from thelowpressure side substantially balances said gate, said valve body havingchambers in the end thereof beyond said gate, and means for maintainingsaid chambers in communication with the same source of pressure toequalize the pressure on th ends of said gate.

6. A balanced valve having a body with a high pressure connection on oneside thereof and a low pressure connection on the opposite side thereof,a gate mounted to slide in saidbody, said gate having a passagetherethrough opening communicatlon between said high pressure connectionand said low-pressure connection and affording means for balancing'theside pressures on said gate, and a pressure. regulator connected withsaidlow pressure connection and. having means formoving said' gate.

7. A balanced valve having-a: body with ahigh pressure connection on onesidethereof and a low pressure connection on the other side thereof, agate sliding in said bodyand having a ductopening communication betweensaid high pressure connection and said low pressure connection affordingmeans-for balancing the side pressures on saidgate, means for balancingthe longitudinal pressures at the ends of said gate, and

automatic means for movingsaid 'gate controlled by the pressure existingin said low pressure connection.

In witness that I claim the foregoing I have hereunto subscribed my namethis 20th day of December, 1909.

. .CLARENCE A. CUMMI-N GS.

\Vitnesses:

F. D. AMMEN, E. A. STRAUsE.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. G.

e EsT AVAlLABLE corv

